This invention relates to flame retardant polymethacrylate compositions. More particularly, this invention relates to flame retardant thermoplastic polymethacrylate compositions comprising a thermoplastic polymethacrylate and a flame retrading amount of the pentate salt of an amino-s-triazine and to a method for rendering thermoplastic polymethacrylates flame retardant.
Methacrylic polymers and copolymers are widely employed in a variety of applications such as for making injection molded parts and in forming fiber, film and sheet materials. The ready processability and weatherability has been a major factor in their wide acceptance. Thermoplastic polymethacrylate resins are, however, generally regarded as flammable, with UL94 NVE burning properties. The use of additive flame retardants is therefore indicated where flame retardant properties are required.
Flame retarded polymethacrylate compositions containing halogen-phosphorus compounds or phosphorus compounds which exhibit self-extinguishing, UL V-O characteristics are well known. For some applications the use of halogen-phosphorus compounds or phosphorusbased additive flame retardants is not desirable. Many phosphorus compounds, for example, tend to plasticize polymers and alter the physical properties. Similarly, halogen-phosphorus based flame retardants, whether used alone or in conjunction with synergists such as antimony oxides may alter key physical properties of the resin and limit the potential end uses. An alternative flame retardant for use in these resins would thus broaden the choices available to the resin compounder for meeting the demands of the market.